Black toner and image forming method

Abstract

A black toner includes: toner mother particles containing carbon black as a colorant and a binder resin, the toner mother particles being surface-modified with a polyalkyleneimine.

1. A black toner comprising: toner mother particles containing carbon black as a colorant and a binder resin, the toner mother particles being surface-modified with a polyalkyleneimine, wherein the binder resin contains a rosin resin. 
     
     
       2. The black toner as claimed in  claim 1 , wherein the polyalkyleneimine is polyethyleneimine. 
     
     
       3. The black toner as claimed in  claim 1 , wherein the polyalkyleneimine has a number average molecular weight of from 5,000 to 100,000. 
     
     
       4. The black toner as claimed in  claim 1 , wherein the rosin resin has a softening point of from 80 to 190° C. 
     
     
       5. The black toner as claimed in  claim 1 , wherein the rosin resin has a weight average molecular weight of from 500 to 100,000. 
     
     
       6. An image forming method using a black toner, comprising forming an image with an image forming apparatus through charging, exposing, developing, transferring and fixing, the black toner comprising: toner mother particles containing carbon black as a colorant and a binder resin, the toner mother particles being surface-modified with a polyalkyleneimine, wherein the binder resin contains a rosin resin. 
     
     
       7. The image forming method as claimed in  claim 6 , wherein
 the image forming apparatus comprising: 
 a latent image supporting member that supports a latent image, and 
 a developing device that applies the black toner to the latent image supporting member to visualize the latent image as a toner image, 
 the developing device containing: 
 a toner housing part that houses the black toner, and 
 a developing roller that faces the latent image supporting member adjacently and has a relief structure on an outer circumference surface thereof for supporting the black toner, 
 the relief structure being formed by a rolling method.